1. Field of the Invention
The present invention concerns a camera arrangement for an automobile.
2. State of the Art
A camera arrangement of the above-mentioned kind is known from DE 101 15 043 A1. Here, a method and a device for calibrating a camera system are described, in particular a camera system mounted on a vehicle, with which calibration of the camera in a camera coordinate system in relation to a reference camera system is to be made possible in a simple manner.
Here, however, it is only a question of adjustment or alignment of the camera within the above-mentioned coordinate systems, in particular alignment with a predetermined point in space. Suitable adjustment of the objective lens to the image chip used in the camera, for example, in order to ensure the necessary homogeneous focus of the camera, is not proposed here.
The camera arrangements used in the field of vehicle technology must be set to an optimum focus at the factory. In the process, it must be taken into consideration that these are not cameras as used in the field of professional video recording, for example, but small cameras which are fitted with a small, usually two-dimensional image sensor and an objective lens, the objective lens being connected to the image sensor by a connecting means. To set the required focus, it is provided that the distance from the objective lens to the image sensor is varied until the image sensor delivers an image of sufficient focus. It must, however, be noted that, with the known camera arrangements, tilting of the image sensor (tilting of the image sensor to the printed circuit board plane which differs from the nominal value) must be expected. In this case, values of 2 degrees are fully within the permitted tolerance range. The consequence of this is, however, that, for example, with a focus range of about 0.05 mm on the image side, a focal length f=2 mm and with a stop number of 2.0, tilting the image sensor by 2 degrees leads to only part of the whole image sensor surface being capable of being brought into focus. The remainder or image section remains out of focus.
This is where the present invention comes in and makes it its object to provide a camera arrangement which, in spite of tilting of the image sensor, can be focused in the whole of the image region.